The Butterfly Effect Hypothesis
by Lady Mirelle
Summary: When Howard and Raj do something that seems to be breaking the entire social group apart, and with Priya AWOL, Leonard comes up with a drastic solution that also addresses some hidden feelings. Rated M for strong language and very suggestive adult themes. 1-shot. Some Wolopali but mostly Shelnard.


The Butterfly Effect Hypothesis

Leonard was flabbergasted. His mind jumped first to shock. Numb shock accompanied by a severe, burning blush. Then he thought of Bernadette.

_Poor Bernadette! How the hell is she gonna deal with this_? Then he realised they should have seen it coming.

He swallowed hard, becoming unglued from the spot he stood in, holding the door handle in one hand and a bag of Thai food in the other. His mouth opened and closed a few times before the words found their way out.

"Uh … Priya's not here then?"

A very naked Wolowitz grabbed a cushion and covered himself. An equally naked Koothrappali stuttered, "No," turning an odd shade of purple, hiding behind Howard.

"I'll … uh … leave you to it then." Leonard turned and shut the door behind him. He was sweating and felt nauseous.

"_You mean nauseated," _Leonard could hear his "best friend" and roommate chime for the hundredth time.

Leonard skipped down the stairs. By the time he reached the bottom he knew he needed to throw up. He carefully placed the Thai food on the floor then threw his head into the nearest trash can.

* * *

"I don't understand," Sheldon complained, "Is that socially normal?"

"Sheldon, I've been through this four times already. Howard is about to get married, so finding him naked, having sex with his best friend while his fiancée is on a girls' night is NOT NORMAL." Leonard lost his cool and screamed the last two words at Sheldon, who stumbled backwards in surprise.

"What are you going to do?" Sheldon asked, after taking a moment to regain composure. Leonard wished he could get his cool back like that.

"I guess I'll have to tell Bernadette," he shrugged, taking a swig of his beer to steady himself. "She's staying at Penny's tonight with Amy so …"

"She'll have them to console her and reassure her that it isn't her fault that her fiancé is homosexual," Sheldon finished for him.

"Yeah, something like that," Leonard sighed. He took off his glasses and rubbed his eyes with his forearm.

"You seem to be very distressed about this," Sheldon pointed out with his usual stunning accuracy.

"You don't say?" Leonard scoffed, "Two of my best friends just hooked up, probably ruining the marriage of one of them … and the other is my girlfriend's brother! This could destroy our entire social group so no, Sheldon, I'm not distressed. I'm jumping for joy."

Sheldon paused. "Sarcasm?"

Leonard didn't bother to reply, instead opting to peer over his glasses in a disgusted expression.

"Can I offer you a hot beverage?" Sheldon continued. "Tea? Cocoa?"

"No thank you. I wouldn't mind another beer though," Leonard replied, feeling grateful that his roommate was trying to cheer him up.

"Go and get one then."

"Sheldon! I thought you were trying to cheer me up!"

"I am. But the social protocol only extends as far as hot beverages. So you'll have to get your beer yourself."

"Sheldon, will you just do me this one favour this one time and go get me a fucking bottle of beer?" Leonard snapped. Sheldon looked taken aback at his use of a swear word. It wasn't like Leonard to get so angry.

"Okay. Don't get your knickers in a knot," he mumbled.

He brought a bottle of beer to Leonard, who downed a third of it in one go. At the same time, there was a knock on the door accompanied by the sound of female giggling. Leonard waited but Sheldon didn't get up to answer it so he sighed and pushed himself to his feet. He tugged the door open and was met by the sight of Penny, an obviously drunk Amy and Bernadette, who was giggling at Amy.

"Hey Leonard, you guys wanna come round for drinks?" Penny asked. Leonard could only stare at Bernadette, the events of earlier that evening replaying in his head. Eventually he shook his head.

"Sorry Penny, we're going through something kinda difficult right now."

"Aww, sweetie, is there anything we can do to help?"

"Not really. Uh … maybe if I could talk to Bernadette alone for a second?"

"Sure sweetie. Come on Amy." Penny half-dragged Amy into her apartment, leaving Leonard alone at the door with Howard's fiancée.

"What's wrong, Leonard?"

Leonard cleared his throat and resettled his glasses on his nose. "Well … uh, I witnessed something earlier today that I thought you ought to be aware of. I'm really sorry to have to tell you but you really should know."

"Leonard, you're scaring me. What happened?"

"Ok. I went round to Raj's apartment earlier in the evening and I opened the door without knocking and Howard was there and theywerenakedandhavingsex." The last part tumbled out almost incoherently. Bernadette's face kept its normal bright smile for a second, until she realised Leonard wasn't joking. The smile faded as her face fell, turning from anxious to angry in a matter of seconds.

"Are you sure?" she asked.

"Completely. I'm so sorry."

"No, don't be sorry. Thank you for telling me." With that, she promptly vomited on Leonard's feet.

"Those were some foul looking chunks she blew," Sheldon pointed out as Leonard finished cleaning the purple puke from between his toes. "I wonder what they were drinking. I hope Amy isn't suffering the same effect."

"Sheldon, Bernadette threw up from shock, like I did earlier." Leonard sighed heavily, rubbed his forehead then left the bathroom for his own room. He climbed into bed without bothering to change or say goodnight to his roommate.

He struggled to get to sleep. The mental image of Raj's coffee coloured arms wrapped around Howard's pale skin was burned into his brain. There would have to be a confrontation about this tomorrow at work. They couldn't just sit there all day and pretend nothing had happened.

_Knock knock knock_. "Leonard."

_Knock knock knock_. "Leonard."

_Knock knock knock_. "Leonard."

"What is it Sheldon?"

"I can't sleep."

"So count some sheep or take some cyanide or something."

The door clicked open and Leonard rolled his eyes, burying his face in his pillow.

"I can't stop thinking about what you said about Koothrappali and Wolowitz having coitus, that it might destroy our social group."

"I thought you didn't care about anything social." Leonard rolled onto his side and slipped his glasses on. If this was really bothering his roommate this much, he was probably obliged to try and help him. _It's not like I was sleeping anyway_."

"I have spent years rearranging my routines, rearranging your routines, putting up with Penny having noisy "yeehaw" intercourse with you, mocking Wolowitz for not having a doctorate. I have put effort into getting this group to be tolerable. If it just falls apart like this, I think I might lose my mind."

"You are crazy enough as it is," Leonard agreed. He patted the bed beside him and Sheldon sat down.

"I'm not crazy. My-"

"Mother had you tested, I know." Leonard awkwardly patted Sheldon's arm, in an imitation of how Sheldon had consoled him in the past. "There, there," he added. Sheldon didn't get the reference to his own uncomfortable comforting and just heaved a heavy sigh.

"Will you sing Soft Kitty to me?"

Leonard grunted, standing up and pulling his bathrobe on. "Soft Kitty's for when you're sick."

"Being worried and sleep-deprived is a type of being sick," Sheldon explained, hopefully. Leonard rolled his eyes.

"Lie down then."

Sheldon stretched out on the bed, his feet reaching much further down than the Leonard-shaped dent. Leonard perched awkwardly next to him and started to sing the song in a groggy voice. Before he was through, Sheldon was asleep. Though he knew Sheldon would object in the morning, he was too tired to drag himself into the living room so he curled up next to his roommate. It was a difficult sleep but the warmth and physical closeness to a person – even if that person was nearer praying mantis than human – helped him fall asleep. The last thought in his mind before he drifted off: where was Priya through all this?

* * *

The next morning brought an awkward silence in the car on the way to work. Sheldon had woken up cuddling Leonard and panicked, which resulted in Leonard sporting a nosebleed and Sheldon a black eye. At the university, the atmosphere wasn't much better. Leonard didn't even see Howard or Raj until almost noon, when he heard a soft knock on his office door.

"Come in."

It was Howard, looking very, very uncomfortable.

"Oh, Howard, I'm glad you're here. Listen, we need to talk about yesterday-"

"I know, that's why I came to talk to you. I need you to tell me I'm not crazy. I know I've hurt Bernadette but I didn't plan this, I'd never have done it intentionally. It just happened. I love Bernadette but being with Raj just … happened."

"Okay, if you want me to reassure you that you're not insane you'll have to explain yourself a bit better." He gestured for Howard to sit down. "Start at the beginning. What provoked this? I mean, I know my mother saw this coming, years ago but something must have triggered this. Alcohol?"

"We were sober, actually." Howard was blushing profusely. "It all started a few months ago. You remember Raj got some time on that space telescope and he invited me along, and I took Bernadette? Well, we had some wine and things were going really nicely, when Raj took a turn to the dark side. He was whining about how he's never going to get a girl and he'll die alone. The usual."

Leonard nodded, scribbling notes down from the story in a notebook.

"So Bernie tried to reassure him by telling him he was a great guy and the right girl was out there, but he just needed to look for her. He was drunk, so he tried to kiss her and I leapt in front of her and he ended up accidentally kissing me." Howard paused and cleared his throat. "It's been kind of a butterfly effect since then. I couldn't stop thinking about it and he told me later that he couldn't stop thinking about it but we didn't do anything about it. He was a bit depressed and distracted for a while, especially when we were carrying on with the wedding preparation, so last night I invited him round for some video games. He wanted to be sans Sheldon, otherwise I'd have invited you too." He cleared his throat again, getting visibly on edge. His eyes flicked to the closed door.

"Go on, I'm still listening." Leonard tried to sound soothing and neutral. He hated seeing his friend in such distress.

"Well, we got to talking and he said he might actually have feelings for me. I didn't know how to respond so I just sat there, and he leaned forwards and kissed me. Really tender and soft … It kind of … tugged at places that kissing Bernie never did. Like my stomach. It just flipped over and over and I couldn't stop kissing him back and … well, a butterfly flaps its wings and one thing leads to another, you know?" he smiled uneasily, signalling the end of his story.

"I don't think that's crazy," Leonard concluded. "It's stupid, and you're probably putting our social group at risk but it's not crazy." Leonard's own stomach was plunging with the realisation that it didn't flip when he kissed Priya. It flipped when he kissed Penny.

"What am I gonna do, Leonard? Bernie called me last night and she was really upset and she called off the wedding and she doesn't want to talk to me …" He trailed off, sniffing back tears.

"Okay," Leonard began, trying to keep his head neutral and unemotional. "Here's what I think you should do. Give Bernadette time to cool off then call her and tell her what you just told me. Second, have some time away from Raj. You need to sort out your head and figure out who you want to be with."

Howard nodded and took a steadying gulp of air. "You've been spending too much time with Penny; you're actually making sense about a relationship problem," he joked. "Thanks man," he added, before leaving. Leonard set to his work, a tense knot forming in his stomach, which stayed there until long after he returned home. He relayed Howard's story to Sheldon in the car after work.

"Relationships baffle me," Sheldon complained, "Why didn't Wolowitz just tell Bernadette he was having feelings for Koothrappali? Surely then this whole mess would have been avoided."

"When you put it that way, it seems simple," Leonard admitted, "But you need to take into account the fact that they were both pretty much in denial-"

"Even though your mother identified their homosexual feelings years ago," interrupted Sheldon.

"They were in denial, anyway, so it was difficult for them to even admit it to themselves, let alone to Howard's ex-future wife."

"I know what denial means," Sheldon grumped. Leonard couldn't help but smile. At least in "this whole mess" one thing would never change – Sheldon's ego.

It was becoming a habit for the two of them to make this exchange.

"I don't want tea," was Leonard's response, "But if you could get me another beer-"

"The invitation only extends as far as _hot_ beverages, so get your own beer," replied Sheldon, settling into his spot to watch "Star Trek: the Search for Spock". Leonard bit back a filthy word and just fetched his own drink this time.

There was a loud, rough knocking on the door. "Leonard!" It was Penny, sounding more pissed off than he'd ever heard her – and that was saying something.

Leonard quickly got the door and was faced with a very angry Nebraskan carrying a wok.

"What the hell happened last night?" she screamed, causing Sheldon to almost jump out of his seat. Leonard took a step back, while Penny took a step forward. "Bernadette has been in my apartment all day _crying her eyes out_ and she won't tell me what happened, she won't go home and I HAD TO TAKE THE DAY OFF WORK TO MAKE SURE SHE DIDN'T TRY TO HANG HERSELF!"

Leonard felt a fierce blush spread across his face. He was going to have to tell her.

"What did you do?" she demanded.

"N-nothing!" Leonard exclaimed, taking another step back. Penny was brandishing that wok in a scarily violent manner. "I went round to Raj's last night to see Priya and …" He hesitated, unsure if it was really his place to say.

"What – did – you – do? "

"Well, I opened the door and … well, Raj and Howard were "doing the dance with no pants". Then I told Bernadette when you guys got back last night."

"Oh my God. I mean, we all saw it coming but I never thought it would actually happen. God, Bernadette must be feeling so humiliated. Do you know how it happened?"

Leonard told her what Howard had told him and Penny's reaction was predictable.

"Of course it was crazy! He was ENGAGED! He could've stopped himself. God, that's disgusting. I swear I'm never gonna talk to him ever again."

"You'd understand better if it was him telling the story," Leonard offered. "His eyes … you could see in his eyes what this was doing to him."

Penny raised the wok threateningly. "I'll tell you what _I'll_ be doing to him-"

"Please just tell Bernadette what Howard's going through and try to get her to call him?" The look on Penny's face made him regret that he'd said that.

"Why the Hell should I? That sick bastard can call her and explain himself!" She spun on the spot and left, slamming the door behind her.

"She's never going to want coitus with you after this," Sheldon pointed out, bluntly. Leonard stopped himself from throwing his unopened beer at his head.

Leonard couldn't concentrate on the movie. He excused himself and went to bed early. He'd just drifted off when-

_Knock knock knock._ "Leonard."

_Knock knock knock._ "Leonard."

_Knock knock knock._ "Leonard."

Leonard didn't respond, but the door opened anyway. He sat up, exasperated.

"Sing Soft Kitty to me?" Sheldon asked, looking forlorn.

"Soft Kitty's for when you're sick." It struck him that he sounded like Penny, and his stomach flopped unpleasantly.

"Being an insomniac is a type of being sick."

"you're not an insomniac," Leonard groaned but obliged. He pulled himself out of his bed and followed Sheldon to his room. He'd never been allowed into Sheldon's room before, so he savoured the moment, smiling to himself in inappropriate amusement as Sheldon got under the covers.

Leonard started to sing. "Soft kitty, warm kitty, little ball of fur-"

"You need to stroke my hair," Sheldon interjected.

Leonard frowned. "I didn't stroke your hair last night."

"Well tonight I'm even more sleep-deprived and my mother always strokes my hair when I'm sick."

"Fine," Leonard sighed, too tired to object. He ran a hand along Sheldon's head; being gentle considering only hours ago he had refrained from splitting the man's skull with a beer bottle. Leonard sang the song, softly if a little coarsely, whilst stroking Sheldon's hair. He was starting to feel slightly tender towards him. He imagined this might be how he would feel about his children. Sheldon was batshit crazy but he did look quite sweet when he was sleeping.

As he was leaving the room, Sheldon called out in a little voice, "Leonard?"

"What is it now?"

"Thank you."

Leonard smiled to himself. His stomach flipped pleasantly.

* * *

Leonard woke with a start from a disturbing dream. He had dreamt that he was seeing the scene in Raj's apartment, but instead of Howard and Raj, it was Sheldon and himself. He was covered in sweat, panting, and had an erection.

"Oh God," he wheezed, flopping backwards onto his pillow. It took a whole ten minutes and a long puff on his inhaler to get his breathing back to normal.

_Knock knock knock. _"Leonard?"

It was Sheldon's tentative whisper through the wall.

"What?"

"Are you alright? You were moaning in your sleep and then you were breathing really fast. I just wanted to check you didn't die."

Leonard bit his pillow to stop himself from screaming at his roommate. "Good to know you care, buddy," he snarled, voice dripping with sarcasm.

"My pleasure," replied Sheldon, missing the sarcasm completely, "I platonically love you, and it would leave an empty, unproductive space in my apartment if you died."

Leonard's stomach did a massive dive at the word "platonically". He knew it was just a stress reaction caused by a huge, sudden release of adrenaline, but it was enough to make him feel queasy. Before he could engage his brain, his feet had taken him down the hall into Sheldon's bedroom. Without knocking.

"You can't be in my room!"

Leonard hesitated in the doorway. His heart was pounding painfully.

_I have to do this, _he told himself, _and it's now or never. I should know one way or the other._

He nodded to himself, riding the wave of adrenaline that had enveloped him, and approached Sheldon's bedside.

"What are you doing?" asked Sheldon, sitting up in alarm. Leonard threw himself forwards onto his roommate's bed and crushed Sheldon's mouth under his own.

Sheldon froze underneath him. When he released him for some air, the taller man sat up, making Leonard feel suddenly small.

"What are you doing?" demanded Sheldon, his expression an amalgamation of many emotions. There was fear, bemusement and confusion, to name but a few.

Leonard stopped himself from saying what he really wanted to say. His mind was clearing a bit but he was down the rabbit hole already, so what the hell?

"If Howard and Raj can do it-"

"You've been complaining all day about Howard and Raj risking the integrity of our social group, and now you want to join in?" Sheldon stared at Leonard, one thin eyebrow raised.

"When you put it like that, I can see how the logic would seem flawed, but if you really think about it this is the only way to keep the group together."

Sheldon paused. "I accept your hypothesis. Having run scenarios in my mind, I conclude I cannot think of a better solution. But that doesn't change the fact that I don't like people touching me."

Leonard bit back a laugh. The inappropriate timing of it was also funny, so he ended up chuckling anyway.

"What was that evil laugh for? Are you planning to cut me in half with a laser beam?"

"No," Leonard grinned, "You're just a total skxawng when it comes to people. It made me laugh."

"If you're going to sit there and insult me I'm getting up to make some hot milk."

Placing a hand on his friend's shoulder, Leonard stopped him from getting up. He brought his face really close to Sheldon's and whispered, "Aren't you even a little bit curious about how it feels?"

Sheldon's answer was hesitant, so Leonard just kissed him again. It was kind of like kissing a door, but it afforded him the time to snake his hands down Sheldon's pyjama bottoms. Sheldon tore his face away and spluttered, "Did I not just tell you I don't like people touching-"

The next sound that came from him was a mixture of a throaty moan and a plea to a deity he didn't believe in. "Okay, I changed my mind," he conceded as Leonard gently moved his hand.

Sheldon's entire body felt sore when he woke up the next morning, just seconds before his alarm went off. He couldn't imagine how sore poor Leonard must be feeling. As he sat up and threw the covers off himself, there was a loud thump. Leonard had fallen off the bed.

"Ouch," he groaned. He groaned again as he felt the soreness of his body. The night's events flooded back to him and he sat up, looking curiously at Sheldon.

"Good morning," Sheldon smiled. Well, it wasn't a smile as such, but his voice was bright. Leonard took that to mean he wasn't angry at him.

"Good … morning?" came the tentative reply from the floor.

"Are you asking me if it's morning?"

"No, I was returning your greeting!"

Sheldon frowned. "We had this same problem the day you moved in here. Questioning intonation confuses me."

With that, he got up and left Leonard on the floor. Before the clock struck 7.30, Leonard's phone buzzed. _Priya. Shit._

The shower ran for a lot longer that morning.


End file.
